Expression of IgE heavy chain transcripts in the sinus mucosa of atopic and nonatopic patients with chronic sinusitis

We have recently shown the increased mRNA expression of interleukin (IL)-4 and IL-13 in sinus biopsies from allergic subjects with chronic sinusitis (ACS), whereas only IL-13 mRNA was elevated in biopsies obtained from nonallergic subjects with chronic sinusitis (NCS). In the lymph nodes and spleen, these cytokines may promote IgE production through transcriptional activation of the germline IgE heavy chain promoter, an event which precedes immunoglobulin isotype switching to IgE in B cells. We hypothesized that local expression of IL-4 and/or IL-13 might act by inducing germline IgE heavy chain transcript expression locally in the sinus mucosa of chronic sinusitis patients. Mucosal sinus biopsies were obtained from 13 patients with ACS, 12 subjects with NCS, and 11 normal control individuals. The numbers of B cells in the sinus mucosa were studied by immunocytochemistry with anti-CD20 monoclonal antibodies. In situ hybridization was performed using antisense radiolabeled riboprobes complementary to the IgE epsilon -heavy chain germline (Iepsilon) and heavy chain constant region (Cepsilon) gene transcripts. Riboprobes specific for the IgG gamma-heavy chain constant region (Cgamma) were used as an isotype control. Immunocytochemical analysis indicated augmented numbers of CD20-positive B cells in the biopsies obtained from ACS patients compared with NCS subjects (P < 0.05) and normal control subjects (P < 0.01). Statistically significant increases were observed in the numbers of cells expressing Iepsilon and Cepsilon transcripts in the sinus mucosa of ACS patients compared with those with NCS (P < 0. 001) and normal controls (P < 0.001), while Cgamma RNA expression did not differ significantly between the groups. In three randomly selected ACS biopsies, 92-100% of cells expressing Cepsilon transcripts and 100% of Iepsilon RNA-positive cells coexpressed CD20 immunoreactivity. Cells expressing Cepsilon transcripts were also significantly increased in NCS compared with normal controls (P < 0. 05). The results of this study suggest that local IgE class switching occurs in the pathogenesis of ACS and that ACS and NCS are both associated with increased expression of Cepsilon transcripts.

Pulse shapes and stability in Kerr and Active Mode-Locking (KAML)

We present numerical simulations of laser mode-locking using a spatio-temporal master equation. We look at active mode-locking using an amplitude modulator and compare the results with those found using a phase modulator. We find gaussian pulses and stability conditions consistent with the Kuizenga-Siegman theory of mode-locking. We then add a Kerr medium to the cavity and examine the effect this has on the mode-locking process, the stability, and the shape of the final pulses. We find that the pulses are significantly compressed in both space and time, and the profiles become more sech-like.

Stroke prevention trial in sickle cell anemia

Stroke occurs in 7-8% of children with Sickle Cell Disease (Hb SS) and is a major cause of morbidity. Rates of recurrence have been reduced from 46-90% to less than 10% through chronic blood transfusions. Prevention of first stroke, however, would be preferable because even one stroke can cause irreversible brain injury. Transcranial Doppler (TCD) ultrasound can detect arterial blood flow rates associated with subsequent stroke risk. By combining TCD screening and a potentially effective treatment, first stroke may be prevented. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) is the first stroke prevention trial in Hb SS and the first randomized, controlled use of transfusion in Hb SS. This multi-center trial is designed to test whether reducing sickle hemoglobin to 30% or less with periodic blood transfusions will reduce first-time stroke by at least 70% compared to standard care. Primary endpoints will be clinically evident symptoms of cerebral infarction with consistent findings on Magnetic Resonance Imaging and Angiography (MRI/MRA) or symptomatic intracranial hemorrhage. Secondary endpoints will be asymptomatic brain lesions detected by MRI in brain areas not involved in primary endpoints. The design calls for a 6-month start-up interval, 18 months of TCD screening and randomization, and observation for stroke from entry through month 54. Key features of the trial are standardized TCD and MRI/MRA protocols interpreted blindly, and blinded adjudication of endpoints. The sample size (60 per treatment group) is based on prospective data relating TCD velocity to risk of stroke. A time-averaged mean velocity of > or = 200 cm/sec is associated with a 46% risk of cerebral infarction over 39 months. The sample size is sufficient to detect 70% reduction in the primary endpoint at 90% power. This trial will determine if transfusion is effective in the primary prevention of stroke. Secondary aims may further the understanding of the effects of transfusion on the brain and guide future research into cerebrovascular disease in Hb SS.

A randomised prospective comparison of operative peripheral iridectomy and Nd:YAG laser iridotomy treatment of acute angle closure glaucoma: 3 year visual acuity and intraocular pressure control outcome

AIM

To compare visual acuity and intraocular pressure outcomes 3 years after treatment of acute angle closure glaucoma (AACG) by operative peripheral iridectomy (PI) or Nd:YAG laser iridotomy (YAG PI).

METHODS

A prospective study of consecutive patients presenting to one ophthalmology department with uniocular AACG during a 2 year period. Following informed consent patients were randomised to bilateral PI or bilateral YAG PI. Three years after treatment the mean Snellen visual acuity converted to logMAR scores of the two groups was compared using the unpaired Student's t test. The number of patients with normal intraocular pressure with no further treatment in each group was compared using the chi 2 test with Yates's correction.

RESULTS

21 patients underwent bilateral PI and 27 bilateral YAG PI. Three years after treatment visual acuity was 0.30 (SD 0.28) log MAR units for PI eyes and 0.57 (0.67) logMAR units for YAG PI eyes (p = 0.08, NS). 15 (70.4%) PI eyes and 19 (71.8%) YAG PI eyes had an intraocular pressure less than 21 mm Hg with no further treatment (NS).

CONCLUSIONS

There was no significant difference in visual acuity or intraocular pressure control 3 years after treatment of AACG with PI or YAG PI.

Expression of the Sox11 gene in mouse embryos suggests roles in neuronal maturation and epithelio-mesenchymal induction

Sry, the mammalian Y-linked testis determining gene, is a member of a family of genes known as Sox genes, which encode transcription factors related by a DNA-binding motif termed the HMG box. Sox genes are known to have diverse roles in vertebrate differentiation and development. We report here the cloning and characterisation of one of these genes, Sox11, in mice. In addition to an N-terminal HMG box domain, the deduced SOX11 protein contains a number of highly conserved C-terminal motifs, which may function in transcriptional regulation. Expression of Sox11 in mouse embryos was prominent in the periventricular cells of the central nervous system, suggesting a role in neuronal maturation. Expression was also observed in a wide range of tissues involved in epithelial-mesenchymal interactions, suggesting an additional role in tissue modelling during development.

A controlled trial of an educational program to prevent low back injuries

BACKGROUND

Low back injuries are common and costly, accounting for 15 to 25 percent of injuries covered by workers' compensation and 30 to 40 percent of the payments made under that program. The high costs of injury, the lack of effective treatment. and the evidence that there are behavioral risk factors have led to widespread use of employee education programs that teach safe lifting and handling. The effectiveness of those programs, however, has received little rigorous evaluation.

METHODS

We evaluated an educational program designed to prevent low back injury in a randomized, controlled trial involving about 4000 postal workers. The program, similar to that in wide use in so-called back schools, was taught by experienced physical therapists. Work units of workers and supervisors were trained in a two-session back school (three hours of training), followed by three to four reinforcement sessions over the succeeding few years. Injured subjects (from both the intervention and the control groups) were randomized a second time to receive either training or no training after their return to work.

RESULTS

Physical therapists trained 2534 postal workers and 134 supervisors. Over 5.5 years of follow-up, 360 workers reported low back injuries, for a rate of 21.2 injuries per 1000 worker-years of risk. The median time off from work per injury was 14 days (range, 0 to 1717); the median cost was $204 (range, zero to $190,380). After their return to work, 75 workers were injured again. Our comparison of the intervention and control groups found that the education program did not reduce the rate of low back injury, the median cost per injury, the time off from work per injury, the rate of related musculoskeletal injuries, or the rate of repeated injury after return to work; only the subjects' knowledge of safe behavior was increased by the training.

CONCLUSIONS

A large-scale, randomized, controlled trial of an educational program to prevent work-associated low back injury found no long-term benefits associated with training.

Ongoing Y-chromosome instability defines sub-clonal variants in radiation-induced leukaemias in the mouse

Forty primary leukaemias that arose in vivo as a consequence of 3 Gy X-irradiation of inbred mouse strains were analysed for Y-chromosome aberrations by conventional cytogenetics and fluorescent in situ hybridization (FISH). Compared with control mice which were X-irradiated but which exhibited no overt signs of leukaemia, the loss and gain of Y-chromosomes in leukaemic spleen cells defined subclonal variants in the radiation-induced haemopoietic malignancies that arose in CBA/H, DBA/2 and (C57BL/6 x DBA/2)F1 mice. This Y-chromosome instability was significantly higher than that observed in spleen cells of age-matched (or older) irradiated control mice that had not developed overt leukaemia. The detection of Y-chromosome aberrations is considered in the context of the high numbers of potential gene regulatory sequences in the murine Y-chromosome and the potential for the insertional activation of cellular genes during multi-stage radiation leukaemogenesis.

Mini- and microsatellite mutations in radiation-induced acute myeloid leukaemia in the CBA/H mouse

Radiation-induced acute myeloid leukaemia (AML) in the CBA/H mouse is a clonal disorder and therefore amenable to the analysis of genetic instability during radiation leukaemogenesis. The genotype of a single minisatellite and 20 microsatellite loci was compared in tail and leukaemic spleen DNA prepared from the same mouse. Somatic mutation at the Ms6-hm minisatellite locus was nearly seven times higher (27%, 4/15) than the spontaneous germline mutation rate (4%). Only 1/15 AMLs exhibited microsatellite mutations, but 5/20 loci were mutated in the same AML, indicating that it was deficient in mismatch repair. Thus, whereas somatic minisatellite mutations, which are associated with complex intra-allelic gene conversion events, occur at a very high rate in the radiation-induced AMLs, microsatellite instability, which has been associated with the acquisition of the replication error repair (RER+) phenotype, is infrequent but detectable.

Fertility and reproductive choice in women with HIV-1 infection

OBJECTIVE

To measure fertility and birth rates and to describe the reproductive histories of women diagnosed with HIV-1 infection in Australia.

METHODS

The medical records of 294 women with HIV-1 infection in four states of Australia were reviewed. Expected fertility and birth rates were calculated using national statistics.

RESULTS

In the study population, 152 (52%) women had at least one pregnancy prior or subsequent to HIV-1 diagnosis. At maternal HIV-1 diagnosis, 71 (24%) women had a total of 106 children aged under 15 years. During the study period, 246 women were aged 15, 44 years and 58 (23%) of these became pregnant after HIV-1 diagnosis. Women whose exposure to HIV-1 was injecting drug use were twice as likely to become pregnant and more likely to have multiple pregnancies than women who did not report injecting drug use. The annual general fertility rate was 30 per 10,000 compared with 63 per 10,000 for the Australian female population aged 15-44 years, and the birth rate in women with HIV-1 infection was one-half that of the general female population. Of pregnancies confirmed after HIV-1 diagnosis, 47% were voluntarily terminated, a rate more than double that of the general population. All multiple terminations were among women whose exposure to HIV-1 was injecting drug use.

CONCLUSIONS

Fertility and birth rates among women with HIV-1 infection are lower than the general population and the rate of termination higher. The results of this study provide a basis for the management of women with HIV-1 infection who are considering pregnancy.

Nonlinear mixed effects modeling of single dose and multiple dose data for an immediate release (IR) and a controlled release (CR) dosage form of alprazolam

PURPOSE

NONMEM was applied to single dose and multiple dose bioavailability data for an immediate release (IR) and a controlled release (CR) dosage form of alprazolam to acquire additional information from the data which are not easily obtainable by traditional means.

METHODS

The objective function value (OBJ) and diagnostic plots were used as measures of goodness of fit of the model to the data. A change in the OBJ value of 7.9 was necessary to show statistical significance (p < 0.005) between two models when the two models differed by 1 parameter.

RESULTS

A two-compartment linear model with first-order absorption and elimination best describes the data. Including a lag time, two different rates of absorption (KAIR and KACR), and bioavailability for the CR relative to the IR dosage form significantly improved the fit of the model to the data. Cigarette smoking was associated with a 100% increase in clearance of alprazolam as compared to non-smokers. The higher residual variability observed in this study, where interoccasion variability (IOV) was not initially modeled, could be explained to a large extent by the presence of significant interoccasion variability (IOV).

CONCLUSIONS

Since alprazolam has been suggested to be mainly metabolized by the CYP3A4 isozyme in humans, it appears that tobacco could be an inducer of CYP3A4 and/or alprazolam may be metabolized by other isozyme(s) (specifically, CYP1A1/1A2) that are induced by cigarette smoke. The population pharmacokinetic model approach combined with exploratory graphical data analysis is capable of identifying important covariates from well-controlled "data rich" Phase I studies early in drug development.

SOX9 binds DNA, activates transcription, and coexpresses with type II collagen during chondrogenesis in the mouse

Two lines of evidence suggest that the Sry-related gene Sox9 is important for chondrogenesis in mammalian embryos. Sox9 mRNA is expressed in chondrogenic condensations in mice, and mutations in human SOX9 are known to cause skeletal dysplasia. We show here that mouse SOX9 protein is able to bind to a SOX/SRY consensus motif in DNA and contains a modular transcriptional activation domain, consistent with a role for SOX9 as a transcription factor acting on genes involved in cartilage development. One such gene is Col2a1, which encodes type II collagen, the major structural component of cartilage. We have compared, in detail, the expression of Sox9 and Col2a1 during mouse development. In chondrogenic tissues the expression profiles of the two genes were remarkably similar. Coexpression was detected in some nonchondrogenic tissues such as the notochord, otic vesicle, and neural tube, but others such as heart and lung differed in their expression of the two genes. Immunohistochemistry using an antibody specific for SOX9 revealed that expression of SOX9 protein mirrored the distribution of Sox9 mRNA. Our results suggest that SOX9 protein is involved in the regulation of Col2a1 during chondrogenesis, but that this regulation is likely to depend on additional cofactors.

In vivo analysis of DNA-protein interactions on the human erythropoietin enhancer

The erythropoietin (EPO) gene is one of the best examples of a mammalian gene controlled by oxygen tension. The DNA elements responsible for hypoxia-induced transcription consist of a short region of the proximal promoter and a <50-bp 3' enhancer. The elements act cooperatively to increase the transcriptional initiation rate approximately 100-fold in response to low oxygen tension in Hep3B cells. Two distinct types of transactivating proteins have been demonstrated to bind the response elements in the human EPO enhancer in vitro: one shows hypoxia-inducible DNA binding activity, while the other activity binds DNA under normoxic and hypoxic conditions. We have investigated the DNA-protein interactions on the human EPO enhancer in living tissue culture cells that produce EPO in a regulated fashion (Hep3B) and in cells that do not express EPO under any conditions tested (HeLa). We have identified in vivo DNA-protein interactions on the control elements in the human EPO enhancer by ligation-mediated PCR technology. We show that the putative protein binding sites in the EPO enhancer are occupied in vivo under conditions of normoxia, hypoxia, and cobalt exposure in EPO-producing cells. These sites are not occupied in cells that do not produce EPO. We also provide evidence for a conformational change in the topography of the EPO enhancer in response to hypoxia and cobalt exposure.

[Vascular protection with estrogen. In-vitro and in-vivo effects--mechanisms and clinical implication]

Myocardial infarction is the major cause of death in the western world. Men are more prone to develop coronary artery disease than women of the same age, in whom coronary disease is rare before menopause. Epidemiological data have shown that estrogens are vasoprotective--especially in the coronary circulation--but the underlying mechanisms have been investigated more thoroughly only in recent years. Only up to half of the protective effect of estrogen replacement therapy an be attributed to its positive effects of the lipid profile. However, a large part of this protection is caused by mechanisms distinct from lipid metabolism. It is now known that estrogens also exert effects on vascular function and structure of the vessel wall involving numerous cellular and molecular mechanisms. Actions of natural estrogens on human vascular cells and arteries will be discussed. Estrogens modulate vascular function by increasing nitric oxide production via stimulation of endothelial nitric oxide synthase (eNOS) and decreasing endothelin-1 levels in vivo. Furthermore, 17-beta estradiol is a potent inhibitor of vascular smooth muscle cell proliferation and migration, which play a major role in atherosclerotic vascular disease and in the remodeling process. 17-beta estradiol also acutely affects vascular tone in human arteries and attenuates constriction induced by contractile agonists. Finally, clinical studies showed that 17-beta estradiol can acutely and chronically ameliorate vascular function in women with and without vascular disease. In conclusion, results from clinical and in vitro studies showed positive effects of natural estrogens on vascular function which could explain in part their protective actions against coronary heart disease. Thus, primary prevention of coronary heart disease by estrogen replacement therapy after menopause appears to be a new approach to reduce cardiovascular mortality in women.

Paternal X-chromosome inactivation in human trophoblastic cells

Dosage compensation for X-chromosome-linked genes between male and female mammals occurs by inactivation of one of the two X chromosomes in the female. In somatic cells, either the paternal or the maternal X chromosome is randomly inactivated in a given cell. In contrast, in the extra-embryonic tissues of mice, the paternally-derived X chromosome is preferentially inactivated. The evidence for paternal X-chromosome inactivation in humans is controversial and remains to be clarified. In this study, we have developed a sensitive polymerase chain reaction (PCR) technique to investigate the methylation pattern of the X-linked androgen receptor (AR) gene. The 5' CpG island of this gene is methylated on the inactive X chromosome and hypomethylated on the active X chromosome in somatic cells. The paternal and the maternal alleles of the AR gene may be distinguished by a polymorphism in the number of CAG triplet repeats within the CpG island. As a source of human extra-embryonic tissue, we used chorionic villus (CV) samples from female conceptuses of 10-12 weeks gestation. From a tiny branch of a CV sample, two distinct cell lineages, the trophoblastic and mesodermal lineages, were dissected apart by trypsin digestion and micromanipulation and DNA was extracted separately from these purified tissues. Digestion of the DNA with the methylation-sensitive restriction enzyme, Hpall, followed by PCR amplification revealed that the paternal allele is preferentially methylated in trophoblastic cells, but not in mesodermal cells. These results strongly suggest that the paternal X chromosome is preferentially inactivated in the human extra-embryonic tissues early in development.

Extracolonic features of familial adenomatous polyposis in patients with sporadic colorectal cancer

We have investigated the occurrence of attenuated extracolonic manifestations (AEMs) of familial adenomatous polyposis (FAP) in patients with non-polyposis colorectal cancer. In a prospective case-control study, we observed that significantly more colorectal cancer patients exhibited AEM than did age and sex-matched controls (19.5% vs 7.5%, P < 0.004). However patients with AEMs do not have occult FAP, as we found no heterozygous adenomatous polyposis coli (APC) gene mutations despite extensive analysis of constitutional DNA. Genome-wide DNA replication errors (RERs) occur in a proportion of colorectal cancers, particularly right-sided lesions and in almost all tumours from hereditary non-polyposis colorectal cancer (HNPCC) patients. As AEMs have been reported in familial colon cancer cases, we investigated the relationship of AEMs to tumour RER phenotype. There was indeed an excess of AEMs in patients with right-sided tumours (30.2% of 53 patients vs 14.7% of 116 patients, P < 0.03) and in those with RER tumours (3 out of 12 patients with RER tumours vs none out of 21 patients with non-RER tumours, P < 0.05). Two patients with AEM were from HNPCC families compared with none of those without AEM (P < 0.05). The association of AEMs with colorectal cancer is intriguing, and we speculate that it may be a manifestation of mutational mosaicism of the APC gene, perhaps associated with a constitutional defect in DNA mismatch pair.

Assessing children with traumatic brain injury during rehabilitation: promoting school and community reentry

Children with traumatic brain injuries (TBI) require a comprehensive, multidisciplinary evaluation during rehabilitation to promote recovery and to facilitate a smooth transition to home and school. This article summarizes the common consequences of TBI and reviews a process-oriented approach to assessing children with moderate to severe TBI during rehabilitation. An emphasis is placed on early and regular communication among rehabilitation specialists, family members, and educators. Such collaboration permits clear identification of functional abilities and increases the child's potential for a positive long-term outcome.

Pattern of growth in children with cerebral palsy

OBJECTIVE

To provide a growth reference standard for children with quadriplegic cerebral palsy (QCP). Growth references specific to children with cerebral palsy would facilitate uniformity in clinical appraisal of their growth and nutritional status and would simplify comparative interpretation of growth data.

DESIGN

Weights and lengths were obtained according to standardized procedures. Measurements were taken at time of visit to an orthopedic clinic and from retrospective review of charts.

SUBJECTS

Three hundred sixty children with QCP. Growth data were based on 1,630 observations.

ANALYSIS

Growth curves representing the 10th, 50th, and 90th percentiles were estimated using a smoothing splines technique. Statistical bootstrapping was performed to confirm significant differences from the growth charts of the National Center for Health Statistics (NCHS).

RESULTS

Growth charts were constructed for boys and girls, aged 0 to 120 months, depicting length for age, weight for age, and weight for length. Average differences in length for age, weight for age, and weight for length between children with QCP and NCHS standards were -2.3 z, -2.4 z, -1.3 z for boys, and -2.1 z, -2.1 z, -1.1 z for girls. Children with QCP fell progressively behind in stature and weight. Compared with their NCHS counterparts, they were 5% shorter at 2 years of age and more than 10% shorter at 8 years of age.

APPLICATION

Charts representing the pattern of growth in children with QCP should be accessible to parents and health care professionals to facilitate evaluation and monitoring of nutritional status.

Cholesterol levels in normal Irish adults: the Mater Hospital Cholesterol Screening Survey

Serum samples from 954 Irish adults (604 males, 350 females) aged 18 to 65 years were analyzed within 24 hours of receipt for non-fasting total serum cholesterol levels. The subjects were volunteer blood donors (Blood Transfusion Service Board, Pelican House, Dublin) presenting from June 1990 to February 1991. Serum cholesterol increased significantly with age in both males and females. Mean serum cholesterol in males increased from 4.5 (+/- 0.9) mmol/l in those < 25 years, to 5.7 (+/- 1.0) mmol/l at age 55-64 years. In females, mean serum cholesterol increased from 4.3 (+/- 0.9) mmol/l less than 25 years to 6.2 (+/- 0.8) mmol/l at age 55-64 years. Options for reporting cholesterol ranges are discussed. The overall mean cholesterol concentration of 5.1 mmol/l seen in this study is lower than that reported for comparable studies of U.K. and American subjects, but higher than observed in Japanese individuals. Almost 48% of the studied population had a serum cholesterol value less than 5 mmol/l and over 56% had levels less than 5.2 mmol/l.

Exclusion of Sox9 as a candidate for the mouse mutant tail-short

The Sry-related gene Sox9 has been proposed as the gene responsible for the mouse skeletal mutant Tail-short (Ts), on the basis of its expression in skeletogenic mesenchymal condensations in the mouse embryo and its chromosomal location in the region of Ts on distal Chromosome (Chr) 11. We present here detailed mapping of Ts locus relative to the Sox9, using an intersubspecific cross. Among 521 backcross progeny, 16 recombinants were detected between Sox9 and Ts, suggesting a separation of 3.5 +/- 0.01 cM, and excluding Sox9 as a candidate for Ts. A further nine recombinants were detected between Ts and the polycomb-like gene M33, suggesting that these loci are separated by 1.8 +/- 0.011 cM. Six microsatellite markers were co-localized to the Ts locus, providing reagents for positional cloning of Ts.

Response of families to two preventive intervention strategies: long-term differences in behavior and attitude change

OBJECTIVE

To explore the long-term impact of two forms of preventive intervention designed to diminish risk to children in families in which one or both parents suffered from affective disorder.

METHOD

Fifty-four parents in 18 families were initially assessed and randomly assigned to one of two interventions--a clinician-facilitated, manual-based, psychoeducational preventive intervention or a standardized lecture-group discussion in which similar educational information was presented. Assessments included standard diagnostic interviews, child behavior scales, and semistructured interviews with parents about the effects of the intervention. Follow-up assessments were conducted three times over the 3-year follow-up interval.

RESULTS

No harmful effects were reported for either intervention, and ratings of degree of upset about reported concerns declined across time for both conditions. Families receiving the clinician-facilitated intervention reported more behavior and attitude changes than did lecture-group families when assessed after intervention. The difference between the two groups was sustained at further follow-up assessments.

CONCLUSION

Although both preventive interventions produced changes in behaviors and attitudes, parents in the clinician-facilitated intervention reported more benefit. These data support the hypothesis that linking cognitive information to the family's life experience produces long-term changes.

A polymorphic and hypervariable locus in the pseudoautosomal region of the CBA/H mouse sex chromosomes

We have identified a genomic locus (DXYH1) that is polymorphic and hypervariable within the CBA/H colony. Using a panel of C57BL/6 x Mus spretus backcross offspring, it was mapped to the distal end of the X chromosome. Pseudoautosomal inheritance was demonstrated through three generations of CBA/H x CBA/H and CBA/H x C57BL/6 crosses and confirmed through linkage to the Sxr locus in X/Y Sxr x 3H1 crosses. Meiotic recombination frequencies place DXYH1 similar 28% into the pseudoautosomal region from the boundary. The de novo generation of CBA/H variant DXYH1 restriction fragment length polymorphisms during spermatogenesis is suggestive of the germline instability associated with hypermutable human minisatellites. The absence of DXYH1-related sequences in Mus spretus provides DNA sequence evidence to support the observed failure of X-Y pairing during meiosis and consequent hybrid infertility in C57BL/6 x Mus spretus male F1 offspring.

Eye patch treatment for the pain of corneal abrasion

The traditional use of patching and topical antibiotics in the treatment of corneal abrasion has recently been challenged, particularly after foreign body removal. In a prospective, controlled, randomized study of 33 patients treated in the emergency department for eye pain and corneal abrasion, we attempted to determine whether eye patching affected the pain of simple corneal abrasions. After fluorescein examination with magnification (x 5), a visual analog pain score was recorded and the patient was randomized to either the patched or nonpatched group. A standard analgesic was supplied, and all patients had follow-up at 24 hours, when repeat pain scores and analgesic use were recorded. The groups were compared by using the Wilcoxon's rank sum test, Student's t test, and analysis of covariance as required. There was no significant difference in the mean changes in pain scores between the patched and nonpatched groups. Analgesic use was also similar. We conclude that routine eye patching does not favorably affect the pain associated with the treatment of simple corneal abrasion.

Co-amplification to tail-to-tail copies of MuRVY and IAPE retroviral genomes on the Mus musculus Y chromosome

We have isolated a clone from a C57BL/6 genomic library that contains both part of the Y Chromosome-specific 8.7 kbp MuRVY genome (Hutchinson and Eicher, J. Virol. 63, 4043, 1989) and a full-length 8.3 kbp Intracisternal A Particle genome (IAPE-Y), in a tail-to-tail organization. Although IAPs are encoded by a disperse multigene family (approximately 1000 copies per haploid genome), we present evidence that a significant proportion of the IAP-related sequences are present on the Y Chromosome (Chr) and that a >25 kbp genomic sequence, which contains the two proviral genomes, has been amplified on the Y Chr. Two discrete amplified families of MuRVY retroviral genomes distinguishable by a polymorphic restriction site were detected, suggestive that amplification occurred in incremental stages. The presence of MuRVY-related DNA sequences, but absence of IAPE-Y-related DNA sequences in Mus spretus suggests that the IAPE-Y retrotransposition event occurred after the evolutionary divergence of the lineages leading to Mus musculus and Mus spretus, and that the amplification of MuRVY occurred independently in the two lineages.

Infectivity of a Cryptosporidium species isolated from a domestic cat (Felis domestica) in lambs and mice

Two neonatal lambs were inoculated orally with purified Cryptosporidium species oocysts isolated from a farm cat. Oocysts first appeared in the faeces of the two lambs three and 10 days after infection. Two distinct sizes of oocysts were observed in the faeces of both the cat and the lambs, the smaller measuring approximately 5.0 x 4.5 microns and the larger measuring approximately 6.0 x 5.0 microns in diameter. The smaller type predominated. Histological examination of the alimentary tract of the lambs revealed endogenous stages of Cryptosporidium in the epithelial borders of the ileum. In addition, Cryptosporidium oocysts were detected in impression smears from the jejunum, ileum, caecum and colon. Suspensions of 10(3) oocysts from the faeces of the farm cat were inoculated into each of 10 newborn mice and 10(4) oocysts from the two experimentally infected lambs were inoculated into each of 20 newborn mice. Cryptosporidium oocysts were detected in gut homogenates from 19 of the 20 mice inoculated with oocysts from the lambs but in none of the mice inoculated with oocysts from the cat.

Formation of the ferritin iron mineral occurs in plastids

Ferritin in plants is a nuclear-encoded, multisubunit protein found in plastids; an N-terminal transit peptide targets the protein to the plastid, but the site for formation of the ferritin Fe mineral is unknown. In biology, ferritin is required to concentrate Fe to levels needed by cells (approximately 10(-7) M), far above the solubility of the free ion (10(-18) M); the protein directs the reversible phase transition of the hydrated metal ion in solution to hydrated Fe-oxo mineral. Low phosphate characterizes the solid-phase Fe mineral in the center of ferritin of the cytosolic animal ferritin, but high phosphate is the hallmark of Fe mineral in prokaryotic ferritin and plant (pea [Pisum sativum L.] seed) ferritin. Earlier studies using x-ray absorption spectroscopy showed that high concentrations of phosphate present during ferritin mineralization in vivo altered the local structure of Fe in the ferritin mineral so that it mimicked the prokaryotic type, whether the protein was from animals or bacteria. The use of x-ray absorption spectroscopy to analyze the Fe environment in pea-seed ferritin now shows that the natural ferritin mineral in plants has an Fe-P interaction at 3.26A, similar to that of bacterial ferritin; phosphate also prevented formation of the longer Fe-Fe interactions at 3.5A found in animal ferritins or in pea-seed ferritin reconstituted without phosphate. Such results indicate that ferritin mineralization occurs in the plastid, where the phosphate content is higher; a corollary is the existence of a plastid Fe uptake system to allow the concentration of Fe in the ferritin mineral.

Causes of suppurative keratitis in Ghana

AIMS

Suppurative keratitis is a serious problem in all tropical countries, but very little information is available about the causative organisms in Africa. The objectives were to identify the causative organisms and the proportion of cases caused by fungi in southern Ghana, and to determine whether correct decisions about treatment could be made on the basis of Gram stain in the eye clinic.

METHODS

Scrapings were taken from corneal ulcers of consecutive new patients presenting at Korle Bu Hospital, Accra, and inoculated on 'chocolate' and Sabouraud's agars. Further scrapings were taken for Gram staining and interpretation in the eye clinic. Duplicate slides were assessed by an experienced microbiologist in the UK.

RESULTS

One or more organisms were cultured from 114 of 199 patients (57.3%), the most common being Fusarium species, Pseudomonas aeruginosa, and Staphylococcus epidermidis. Fungi, alone or in combination, were isolated from 56% of the patients who had positive cultures. In total, 122 patients (61.3%) had their treatment either determined or altered based on the results of the microbiological diagnosis; in 87 of these solely on the basis of direct microscopic examination.

CONCLUSIONS

Infection by filamentous fungi accounted for more than half of the ulcers from which cultures were obtained. Both training in technique and experience in interpretation are necessary for microscopy based diagnosis by staff in the clinic to be of greatest value. Direct microscopy was particularly useful for detecting fungi.

The Sry-related HMG box-containing gene Sox6 is expressed in the adult testis and developing nervous system of the mouse

We have cloned and sequenced a full-length cDNA for the HMG box-containing, SRY-related gene Sox6 from mouse. The deduced protein sequence of Sox6 has considerable homology with that of the previously determined Sox5 sequence. It seems likely that these genes have diverged more recently than other members of the SOX gene family, although the two genes map to different chromosomes in the mouse. In common with Sox5, Sox6 is highly expressed in the adult mouse testis and the HMG domains of both proteins bind to the sequence 5'-AACAAT-3'. This suggests that the two genes may have overlapping functions in the regulation of gene expression during spermatogenesis in the adult mouse. However, Sox6 may have an additional role in the mouse embryo, where it is specifically expressed in the developing nervous system.

Emergence of multidrug resistance in Campylobacter jejuni isolates from three patients infected with human immunodeficiency virus

Single-drug resistance to tetracycline, doxycycline, erythromycin, or fluoroquinolones in Campylobacter isolates recovered from humans has been documented worldwide. Multidrug resistance to these antibiotics is rare in Campylobacter jejuni. We report the sequential development of multidrug resistance in C. jejuni isolates from three patients who were infected with human immunodeficiency virus. Multiple isolates recovered from stool specimens from these patients were ribotyped, and antibiotic susceptibility profiles were determined. The results indicated that each patient was infected with a single strain of C. jejuni that had progressively acquired resistance to the antibiotics used during treatment. The emergence of resistant isolates appeared to correlate with clinical relapse. In these patients, campylobacter enteritis was prolonged, severe, and relapsing, and antimicrobial therapy was required. Once these first-line antibiotics become ineffective, few other antibiotics are available for treating patients with campylobacter enteritis. Acquisition of antibiotic resistance in C. jejuni is therefore of concern in these cases.

Predictors of patient adherence to long-term home nebulizer therapy for COPD. The IPPB Study Group. Intermittent Positive Pressure Breathing

STUDY OBJECTIVE

Patients with moderate to severe COPD are frequently prescribed expensive and complicated therapies that require adjustments in usual activities of daily living. However, little is known about factors that are associated with adherence to such treatment. The objective of this study was to identify characteristics of patients who were adherent to long-term home nebulizer therapy.

DESIGN

Patients were stratified into two adherence groups based on average minutes of nebulizer use each day. A logistic regression model was developed to predict adherence based on baseline variables. A questionnaire was administered to patients to assess reasons for adherence to therapy.

SETTING

Five clinical centers in the United States and Canada.

PARTICIPANTS

Nine hundred eighty-five patients with moderate to severe COPD enrolled in the Intermittent Positive Pressure Breathing (IPPB) Trial.

INTERVENTIONS

Long-term home IPPB and nebulizer therapy.

MEASUREMENTS AND RESULTS

Altogether 50.6% of patients were adherent, and 49.4% were nonadherent. Among baseline variables, good adherence was predicted by white race, married status, abstinence from cigarettes and alcohol, serum theophylline level > or = 9 micrograms/mL, more severe dyspnea, and reduced FEV1 (p < 0.05). Subjects who were adherent to nebulizer therapy were older, better educated, had a stable lifestyle, were more likely to report that the therapy made them feel better, and were more likely to keep clinic appointments.

CONCLUSIONS

Sociodemographic, physiologic, and quality of life variables were associated with adherence to long-term nebulizer therapy.

Diode laser treatment for retinopathy of prematurity: structural and functional outcome

AIMS

The anatomical and functional outcome of 13 babies with retinopathy of prematurity (ROP) treated with binocular indirect ophthalmoscope diode laser photocoagulation was assessed.

METHODS

Thirteen babies (25 eyes) at median postmenstrual age (PMA) 25.5 weeks and median birth weight 725 g were treated with binocular indirect ophthalmoscope (BIO) diode laser photocoagulation when threshold retinopathy of prematurity (ROP) was detected at median PMA 35 weeks. Retinopathy was more severe in the nasal retina in 15 eyes. The median severity of retinopathy was 6 clock hours grade 3 disease. All babies were treated under general anaesthetic with no significant ocular or systemic complications during treatment. The median number of burns was 1200.

RESULTS

Resolution of active retinopathy occurred 1-2 weeks following treatment in all but one baby. All eyes had favourable anatomical and functional outcome as defined by the Cryo-ROP study group at a median age of 19.5 months of follow up.

CONCLUSION

BIO diode laser treatment is as effective as cryotherapy with less morbidity.

Comparison of transthecal digital block and traditional digital block for anesthesia of the finger

STUDY OBJECTIVE

To compare the newly described transthecal (TT) and traditional (TD) methods of digital block anesthesia with regard to length of time to achieve anesthesia and pain during infiltration.

DESIGN

Prospective, randomized, controlled, blinded study.

PARTICIPANTS

Healthy adult paid volunteers.

INTERVENTIONS

Each subject received a TT block on one hand and a TD block on the opposite hand. All blocks were performed by the same investigator and were rated by an evaluator who was blinded to the technique that was used. Time to loss of pin-prick sensation was measured, and the pain of the procedure was recorded by the subject on a 10-cm visual-analog scale.

RESULTS

A total of 162 blocks (81 TT and 81 TD) were performed in 31 different subjects. All blocks were successful. Mean time to anesthesia for TT block was 188 seconds compared with 152 seconds for the TD block (P < .01). Mean analog pain score was slightly higher for TT block than for TD block (1.7 versus 1.4, P = .02).

CONCLUSION

TT block is clinically equal to the TD method in terms of time to anesthesia and visual-analog pain score.

Complex Y chromosome aberrations are a recurrent secondary event in radiation-induced murine acute myeloid leukaemia

Arbitrarily primed-PCR analysis of DNA from male CBA/H radiation-induced leukaemic spleens revealed the loss of an approximately 350-bp sequence in several leukaemias. We have isolated a lambda EMBL3 C57BL/6 genomic subclone (pJB1) which hybridizes to the AP-PCR probe and is located on the Y chromosome. Southern blot analyses using the pJB1 probe indicate that the genomic sequence was deleted in five of 14 leukaemias. Cytogenetic analyses of 31 X-ray induced leukaemias in male CBA/H mice revealed, in addition to the characteristic partial deletion of chromosome 2 (28/31 leukaemias), a high incidence (16/31) of the loss of an intact Y chromosome. Comparison of the Southern blot and cytogenetic analyses of the leukaemias demonstrate a significant lack of correspondence between the loss of an intact Y chromosome and Y chromosome-specific DNA sequences, suggesting that Y chromosome aberrations are complex. Whereas partial deletion of chromosome 2 can be detected in 6% of bone marrow cells within 6-11 days of irradiation, no Y chromosome involvement was detected, indicating that Y chromosome aberrations are a late event in radiation-induced leukaemogenesis. These findings are comparable to the loss of sex chromosomes in human t(8;21) AML.

In vitro growth of the microsporidian Septata intestinalis from an AIDS patient with disseminated illness

A new species of microsporidian, Septata intestinalis, was recently recognized as an opportunistic pathogen of AIDS patients. In this study, it was cultured from the nasopharyngeal aspirate of a human immunodeficiency virus type 1-infected patient with disseminated microsporidiosis. In human embryonic lung cells exposed to S. intestinalis, a cytopathic effect appeared within 28 days as foci of rounded up cells. Thin-section electron microscopy showed a variety of developmental stages of the microsporidium within parasitophorous vacuoles. In monocyte-derived macrophages, evidence of infection and development of the parasite was demonstrated by light and electron microscopy. In both infected human embryonic lung cells and monocyte-derived macrophages, a network of septa separated individual spores. Partial sequencing of the RNA small-subunit gene (16S rDNA gene) confirmed the identity of this parasite as S. intestinalis. This is the first report of the isolation of S. intestinalis in vitro and provides evidence that the parasite can be disseminated by macrophages.

An ATF/CREB-binding site is essential for cell-specific and inducible transcription of the murine MIP-1 beta cytokine gene

The murine macrophage inflammatory protein 1 beta mRNA (MIP-1 beta) is rapidly and transiently induced in macrophages by lipopolysaccharide (LPS), serum or cycloheximide. Functional studies of the MIP-1 beta proximal promoter indicate that it is cell-specific, and serum- and LPS-responsive in macrophages. A 76-bp proximal promoter sequence (-51 to -127 bp) confers cell-specific and LPS-inducible activity when placed upstream from a heterologous promoter in both orientations. One essential cis-regulatory element within the enhancer-like sequence is an activating transcription factor/cAMP response element (CRE)-binding protein (ATF/CREB)-binding site, although the promoter is not cAMP responsive. Electrophoretic mobility shift assays and mutational analyses suggest that the promoter site is bound by nuclear protein complexes containing cAMP-independent members of the ATF/CREB family of proteins and c-Jun, and are functionally distinct from the AP1-related TPA-response element (TRE) binding activity.

The Sry-related gene Sox9 is expressed during chondrogenesis in mouse embryos

Mutations in the human SRY-related gene, SOX9, located on chromosome 17, have recently been associated with the sex reversal and skeletal dysmorphology syndrome, campomelic dysplasia. In order to clarify the role of this gene in skeletal development, we have studied the expression of mouse Sox9 during embryogenesis. Sox9 is expressed predominantly in mesenchymal condensations throughout the embryo before and during the deposition of cartilage, consistent with a primary role in skeletal formation. Interspecific backcross mapping has localized mouse Sox9 to distal chromosome 11. The expression pattern and chromosomal location of Sox9 suggest that it may be the gene defective in the mouse skeletal mutant Tail-short, a potential animal model for campomelic dysplasia.

Semiportable electrochemical instrument for determining carbon monoxide in breath

Measurements of carbon monoxide (CO) in breath can be used for the diagnosis of hemolytic disease. A small, semiportable, easy-to-operate CO instrument was developed at Stanford University and tested at 12 Neonatal Research Network Centers of the National Institute of Child Health and Human Development. A syringe pump delivers 7.7 mL of sample per minute through an activate carbon filter to an electrochemical (EC) sensor having a sensitivity of 0.10 +/- 0.01 V per 1 microL/L CO in air. The electronically processed sensor signal is displayed on a digital multimeter. For a typical end-tidal CO measurement, corrected for inhaled CO, three 10- to 12-mL breath and room air samples are manually or mechanically collected and analyzed. CO determination in breath samples from 108 healthy, 1-day-old infants of nonsmoking mothers compared favorably with determinations by gas chromatography (GC), 1.3 +/- 0.8 vs 1.2 +/- 0.8 (mean +/- SD), respectively, with a regression equation of EC = 0.95 GC+0.13 (r2 = 0.98). The results demonstrate that the EC-CO instrument yields results that are comparable with those obtained by the more difficult to perform GC assay.

Use of hemodiafiltration to enhance delivered dialysis

Patients on hemodialysis for end-stage renal disease frequently have increased levels of lipoproteins and beta-2 microglobulin (B2M). In an effort to assess the effect of hemodiafiltration on TACUrea, delivered Kt/VUrea, normalized protein catabolic rate, and B2M level, 6 chronic hemodialysis patients (mean age 63.3 +/- 17 years; 3 men, 3 women) were randomly selected to undergo 4 weeks of hemodiafiltration. The therapy consisted of Qb: 400 ml/min, Qd: 800 ml/min, time: 3.5 hours and 10 L hemofiltrate exchanges with either Ringer's lactate or combination of Ringer's solution and saline using polysulfone membrane dialyzer. TACUrea, Kt/VUrea delivered, normalized protein catabolic rate, serum electrolytes, liver enzymes, lipoproteins, and B2M clearance were evaluated before and after hemodiafiltration. Kt/V increased significantly [pre: 1.3 +/- 0.2 vs post: 1.8 +/- 0.3; p < 0.05], and TACUrea decreased (pre: 44.3 +/- 15 vs post 32 +/- 6.7 mg/dl; p < 0.1). There was no change in normalized protein catabolic rate (pre: 0.88 +/- 0.21 vs post: 0.80 +/- 0.15). B2M clearance was greatly enhanced (pre: 22 +/- 11 vs post: 110 +/- 36 ml/min; p < 0.001) together with a reduction in serum B2M level (pre: 43.6 +/- 11.4 vs 31.2 +/- 6.4 mg/L; p < 0.05). There was no significant increase in total cholesterol, low density lipoprotein, high density lipoprotein, or triglyceride levels, nor was there a change in electrolyte, CO2, or liver enzyme levels. Blood pressure control was satisfactory throughout hemodiafiltration therapy. Hemodiafiltration using a polysulfone membrane dialyzer raised delivered Kt/VUrea and reduced TACUrea and B2M levels significantly.

Semiportable electrochemical instrument for determining carbon monoxide in breath

Measurements of carbon monoxide (CO) in breath can be used for the diagnosis of hemolytic disease. A small, semiportable, easy-to-operate CO instrument was developed at Stanford University and tested at 12 Neonatal Research Network Centers of the National Institute of Child Health and Human Development. A syringe pump delivers 7.7 mL of sample per minute through an activate carbon filter to an electrochemical (EC) sensor having a sensitivity of 0.10 +/- 0.01 V per 1 microL/L CO in air. The electronically processed sensor signal is displayed on a digital multimeter. For a typical end-tidal CO measurement, corrected for inhaled CO, three 10- to 12-mL breath and room air samples are manually or mechanically collected and analyzed. CO determination in breath samples from 108 healthy, 1-day-old infants of nonsmoking mothers compared favorably with determinations by gas chromatography (GC), 1.3 +/- 0.8 vs 1.2 +/- 0.8 (mean +/- SD), respectively, with a regression equation of EC = 0.95 GC+0.13 (r2 = 0.98). The results demonstrate that the EC-CO instrument yields results that are comparable with those obtained by the more difficult to perform GC assay.

Bowel training in spina bifida: importance of education, patient compliance, age, and anal reflexes

Bowel incontinence is a major social impairment for 90% of patients with spina bifida. This study assess the bowel continence of children and young adults with spina bifida before and after a toileting intervention that emphasized patient/family education and a regular, consistently timed, reflex-triggered bowel evacuation. Bowel continence defined as one or fewer incontinent stools per month, rose from 13% (5/40) to 60% (24/40) following intervention. Twenty-four of the 35 initially incontinent patients were compliant. Seventy-nine percent (19/24) of the compliant subjects achieved continence whereas 0/11 of the noncompliant subjects achieved continence p < 0.0001). Presence of the bulbocavernosus (BC) and anocutaneous (AC) reflexes correlated significantly with achieving continence (either vs none p < .02, AC vs no AC p < .01). Instituting bowel training before age 7 correlated with improved outcomes by means of better compliance. Excluding noncompliant subjects, 83% (24/29) of the original sample of 40 patients satisfied our strict definition of bowel continence after this simple low technology intervention.

Reactive astrogliosis in the neonatal mouse brain and its modulation by cytokines

Reactive astrogliosis is a characteristic response of astrocytes to inflammation and trauma of the adult CNS. To assess the hypothesis that cytokines from inflammatory mononuclear cells that accumulate around lesion sites have a role in modulating astrogliosis, this study sought to take advantage of the neonatal system in which astrogliosis is reported to be minimal following injury and in which the immune system is relatively immature compared to adult animals. A nitrocellulose membrane implant into the cortex of postnatal day 3 mice resulted in a tremendous astrogliotic response 4 d later, as measured by glial fibrillary acidic protein (GFAP) immunoreactivity and GFAP content. In contrast, a neonatal stab wound produced limited astroglial response when compared to the adult stab wound. Utilizing the neonatal stab wound model, cytokines were microinjected into the wound site at the time of injury. All cytokines tested (gamma-IFN, IL-1, IL-2, IL-6, TNF-alpha, and M-CSF) resulted in a significantly increased astrogliosis. The specificity of the cytokine response was demonstrated by the inability of human gamma-IFN, but not mouse gamma-IFN, in enhancing neonatal mouse astrogliosis, in accordance with reports that the interaction of gamma-IFN with its receptor occurs in a species-specific manner. We conclude that neonatal astrocytes can become reactive if an adequate injury stimulus is presented, and that the release of immunoregulatory cytokines by cells around lesion sites may be a mechanism that contributes to the production of gliosis.

Screening for retinopathy of prematurity: are a lid speculum and scleral indentation necessary?

We wanted to investigate the value of using a lid speculum and scleral indentation in performing binocular indirect ophthalmoscopy (BIO) in neonates at risk of retinopathy of prematurity (ROP). We performed a prospective masked comparison of BIO examinations using either a lid speculum and scleral indentation (SI) or no scleral indentation (NSI), in our neonatal intensive care unit. We did 57 consecutive BIO examinations of infants weighing less than 1500 g and/or having a gestational age of less than 32 weeks. With NSI, zone I ROP was reliably seen in 53 of 57 examinations; the superior, nasal, and temporal aspects of zone II were seen in 45 of 57 examinations; inferior zone II, in 22 of 57 examinations; and zone III in 1 of 57 examinations. SI facilitated complete peripheral fundus examination in all cases but had to be abandoned in two infants due to acute changes in oxygen saturation levels. Five infants developed threshold disease, and in two of them details of the active ROP ridge were missed with NSI. The gentle use of an eyelid speculum and globe rotation allows rapid and relatively atraumatic assessment of the peripheral fundus, even in babies who are being ventilated. Although threshold ROP may be diagnosed by observation of posterior retinal vessel dilation and tortuosity ("plus" disease), accurate grading of ROP is likely to require SI. In the absence of clearly developed "plus" disease, borderline or prethreshold disease may occasionally be missed using BIO with NSI. SI is necessary to examine the inferior midperipheral retinal vasculature (zone II) and the far peripheral temporal retina (zone III) and is associated with few complications.(ABSTRACT TRUNCATED AT 250 WORDS)